I. Field
The following description relates generally to wireless communications, and more particularly to selectively inserting strip symbols in downlink transmission units in a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various types of communication; for instance, voice and/or data may be provided via such wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources. For instance, a system may use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others.
Common wireless communication systems employ one or more base stations that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast and/or unicast services, wherein a data stream may be a stream of data that can be of independent reception interest to a wireless terminal. A wireless terminal within the coverage area of such base station can be employed to receive one, more than one, or all the data streams carried by the composite stream. Likewise, a wireless terminal can transmit data to the base station or another wireless terminal.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations.
In a time division duplex (TDD) system, the air interface resource may be used alternately as downlink and uplink transmission units with guard time intervals being added in-between. A downlink transmission unit represents a time interval in which the downlink signal is sent, and an uplink transmission unit represents a time interval in which the uplink signal is sent. In the TDD system, the downlink and uplink transmission units are interleaved with each other. When a TDD system is deployed in a cellular environment, the downlink and uplink transmission units of base stations may be synchronized; accordingly, when one base station is in downlink transmission other base stations may also be in downlink transmission, and when one base station is in uplink transmission other base stations may also be in uplink transmission. Since downlink transmission units from disparate base stations may be synchronized, control data such as beacons and the like may be simultaneously transmitted by each of the disparate base stations; thus, a mobile device may encounter difficulty associated with discerning control data provided from differing base stations at common times.